Miller Big Blue 500 engine drives gouge and weld nearly non-stop–sometimes for up to a month–to complete field repairs faster

“Maximum uptime” is the cornerstone of all good service and repair operations. Uptime makes money, and downtime loses money. FEMCO Machine Company of Punxsutawney, Penn. helps companies in the aggregate, mining, crane and scrap industries avoid downtime by machining, welding, and rebuilding equipment to restore it to OEM specifications.

Customers rely on FEMCO for its dependable, experienced workforce (the average tenure is 18 years), quick turnaround times and extensive machining capabilities that include gear cutting, CNC work and the ability to refurbish equipment. FEMCO also offers parts manufacturing, sales and related field service.

In short, customers trust FEMCO to minimize downtime in applications where lost hours mean big losses in revenue. So what does FEMCO rely on to ensure that its service trucks complete field repairs on time and within budget? Big Blue® 500 CC/CV welder/generators from Miller Electric Mfg. Co., as well as service from Miller district manager Bob Jackson and Valley National Gases representative Gary Kahle.

The Big Blue 500 CC/CV withstands FEMCO’s severe-duty use, and it is at the heart of almost every field repair the company makes. On one extremely large job, a Big Blue operated continuously for one month.

“The Big Blue 500 is our lifeline,” states Terry Clark, field service manager, FEMCO. “If our service trucks don’t have this equipment, then we can’t do our job. They have to run, or we’re not working.”

Versatility, Stamina

FEMCO works mainly in the United States but has traveled for work in Africa and Thailand, as well as south of the border to service the South American mining industry. The company’s growth can be attributed to the diversification of its skills: instead of just focusing on one industry or a narrow product line, FEMCO became an expert at welding, machining and repairing heavy equipment in each of multiple industries. It services all makes and models of friction dragline equipment and specializes in crusher rebuilds and field service for aggregates and mining. FEMCO Mining, an offshoot company, rebuilds and resources used mining parts.

Some of its heaviest work comes in the scrap industry. FEMCO sources parts and assemblies from all makes and models of scrap handling equipment. It reverse-engineers hard-to-find and obsolete parts, repairs hydraulic components and rebuilds existing equipment back to OEM specifications. FEMCO has two facilities (Punxsutawney and Pompano Beach, Florida) with crane capacities from two- to 90-tons to accommodate jobs too complicated for work in the field.

Fig. 1

For field work, FEMCO outfits its service trucks with a Miller welder/generator, a crane capable of lifting 6,000 or 10,000 lbs. and every tool needed for site work. (See Fig. 1)

“Over the years, we have tried different welders, and we were never satisfied with other brands,” says Ray Pierce, FEMCO’s assistant field service manager. “The Miller Big Blue engine drives by far have proven themselves, including our five new Big Blue 500 CC/CV units. As long as we perform scheduled maintenance on our Miller diesel engine drives¾and we have Millers on all 17 of our service trucks¾they just seem to run and run. We have flipped the hour meters over on those things, and the motors are still running fine.”

Withstanding Shear Stress

One of FEMCO’s most common repairs is on shear frames used to shear steel in the recycling industry. The components within the shear frame require rebuilding/repair from the extreme stress built up from shearing steel. FEMCO starts by stripping out the steel and brass liners and inspecting the shear frame for cracking using magnetic particle or dye-penetrant tests to detect cracking.

Removing worn or cracked components is no small task: some parts weigh as much as 55,000 lbs. A typical field repair job on a shear frame uses 400 to 500 1/2-in. diameter carbon rods to remove the cracked component.

“I believe that air carbon arc gouging is the true test of a machine,” says Pierce. “We’re going into deep cracks. We can’t just be playing around and just scratching out little bits. We want to drop down an inch-and-a-half and cut as fast as we can go. The faster we gouge, the sooner we can repair the crack. The Big Blue 500 works very well with 1/2-in. carbons. It can drop down and take the deep cut we need to remove steel quickly.”

Once all cracks are gouged out, half-million BTU heaters pre-heat the entire component to 300 degrees F, with temperature monitored using infrared temperature guns. Then, because pre-heat must be maintained on this 1036 steel, FEMCO will weld 24 hours a day, seven days a week until completing the job.

FEMCO uses both the Stick and flux cored process, but emphasizes wire welding for productivity.

“Flux cored is much faster than Stick. It has deposition rates of 6 to 8 lbs. per hour compared to about 2 lbs. per hour, and the weld quality is very good when run correctly,” says Pierce. To combat wind, rain and snow when welding, FEMCO welders “ almost build little buildings around the work area to keep the elements out to better hold the pre-heat.”

A typical frame requires 50-lbs. of Stick electrodes and 900 lbs. of flux cored wire–for six straight days of welding to complete. Two crews weld around the clock, working 12 hours on and 12 hours off.

“Uptime is important to our customers, which is why we choose Miller’s Big Blue engine drives,” says Pierce. “They run 24 hours a day, 7 days a week. On one job, the welders ran for a month. We only shut them down to put fuel in them and check the oil and fired them right back up.”

Clark adds that, “Shear repair places an extensive amount of stress on our Big Blues, especially the gouging because it creates a lot of heat. However, as much as we’ve pounded the daylights out them, I don’t think we’ve ever blown an engine up in our life.”

When long jobs require scheduled engine drive maintenance, FEMCO brings along back-up Miller welders to keep the work going. For the most part, the company relies on the Trailblazer® Pro 350 D, a CC/CV diesel engine drive with a 350 amp welding output and 12,000 watts of single-phase power. If primary power is accessible, the company brings Dimension™ 652 CC/CV electric arc welders, which have a 650-amp output at 100-percent duty cycle. This unit is especially well regarded for its reliability in extreme conditions and ability to gouge with 1/2-in. diameter carbons.

Three-Phase Power

Most of FEMCO’s field work doesn’t allow them the luxury of working in a shop with easy access to power, which is why it relies on the Big Blue 500 single-and three-phase generator power to run grinders, line-boring machines, magnetic drills and portable mills.

Prior to shifting to Miller diesel engine drives 25 years ago, FEMCO used small air-cooled generator/welders with single-phase power. Jerry McAdoo, now a sales and technical support specialist, and once a field service manager, recalls the situation.

"We were out in remote locations where you couldn’t get three-phase power, and that was a problem because portable milling machines require three-phase power,” says McAdoo. “We bought a generator-only unit to produce three-phase power, but that wasn’t very convenient. We wanted generator power, welding power and an air compressor all contained in one machine so that we wouldn’t have to constantly haul around three machines.”

To cut the number of machines from three to two (a welder/generator and a compressor), FEMCO used an “add-a-phase” phase converter to produce three-phase power from single-phase welder generators.

“It got the job done, but it didn’t work all that well,” says Pierce, noting the three-phase power was not strong enough for tools to perform at peak output, slowing repair time. Further, low input voltage also degrades the lifespan of some tools.

To get what they needed, McAdoo and Clark asked their Miller representative for a machine with a strong three-phase output and more welding power. Miller responded and, in 1986, built its first welding generator with a three-phase output, the Big 50. Today, Pierce says that the quality of the three-phase power in the Miller’s Big Blue 500 CC/CV welder “enables our tools to perform exactly the same in the field as they do in the shop. They run just as well if we’re tapped into current at a building.”

Five years back, FEMCO added its own air compressor to the Big Blue via a self-modified jack shaft and drive system. This addition helps FEMCO run all of its tools off of one self-contained unit.

“However, if we had to do it over again, we’d definitely have gone with Miller’s Big Blue® Air Pak™,” says Clark. “The component parts we added to the Big Blue 500 are wearable items, and that increases service-related downtime. With the Air-Pak, there’s fewer components, so it’s more reliable.”

The Big Blue Air Pak “deluxe model” features a 20- to 750-amp multiprocess welding output, strong generator power (20,000 watts three-phase/12,000 watts single-phase) and an Ingersoll-Rand industrial rotary screw air compressor. The compressor produces 100 PSI and 60 CFM, and it can be turned off when not in use. An optional desiccant air dryer system eliminates moisture in the air stream and prevents air line freeze-ups in cold climates. The deluxe model also features 12- and 24-V battery charge and jump start capabilities.

FEMCO began testing the Big Blue Air Pak in 2007 as part of an overall plan to begin upgrading its service truck fleet in 2008. As the company swaps out old trucks for new trucks, each new truck will feature a Big Blue Air Pak. While this unit weighs about 2,000 lbs., its multi-function capabilities reduce overall weight and space.

“DOT regulations allow us to haul only a certain amount of weight,” says Pierce. “Separate engine drives and compressors take away capacity to haul tools and equipment. That means we have to either ship it or send another truck. We no longer have to do that because our one power source supplies everything we need. It frees up space and weight on the truck for our other equipment.”<-->